Hearing Science Test 4 Anatomy Part 2

Front 1

3 rows of cells Located on outside of pillars (rods) of Corti

Back 1

Outer Hair Cells

Front 2

How many rows of outer hair cells have been reported near the apex?

Back 2

4-5

Front 3

Approximately how many outer hair cells in number?

Back 3

12,500

Front 4

Outer hair cells are shaped like a _____________

Back 4

test tube

Front 5

Stereocilia of outer hair cellsform ____ or ____ pattern

Back 5

w, v

Front 6

What are the 3 major types of supporting cells for Outer Hair Cells?

Back 6

Deiters’ cells, Henson’s cells, Claudius cells

Front 7

What are the two main parts of Deiter's cells?

Back 7

main body that rests on BM and holds Outer Hair Cells & phalangeal process that projects to organ of Corti

Front 8

Describe the cytoarchitecture of Inner Hair Cells.

Back 8

extensive endoplasmic reticulum; golgi apparatus & mitochondria (suggestive of high metabolic levels)

Front 9

The cytoarchitecture of Outer Hair Cells has a more extensive subsurface that is similar to _____________

Back 9

muscle.

Front 10

OHCs contain _____________, allowing cells to elongate and contract.

Back 10

contractile proteins

Front 11

Both IHCs and OHCs contain a thickened membrane called a ____________

Back 11

cuticular plate

Front 12

Both IHCs and OHCs have a noncuticular area containing a basal body of a ____________________

Back 12

rudimentary kinocilium

Front 13

The ____________ forms a continuous surface over the hair cells

Back 13

Reticular lamina

Front 14

What forms the reticular lamina?

Back 14

cuticular plate, phalangeal processes, and tops of pillars

Front 15

Highly vascularized tissue that provides nutrients to cochlea.

Back 15

Stria Vascularis

Front 16

What is the role of the stria vascularis?

Back 16

Serves to maintain ionic composition of endolymph in cochlear duct and maintain an electrical potential (endolymphatic potential)

Front 17

The stria vascularis contains a high concentration of __________ (suggesting ____________________)

Back 17

mitochondria; high metabolic levels

Front 18

A Semitransparent, gelatinous membrane that Extends over entire Organ of Corti

Back 18

Tectorial Membrane

Front 19

The Tectorial Membrane extends from _______________ where attachment is ________ to _____________ , where attachment is _________.

Back 19

spiral limbus, strong, outer supporting cells (Henson’s cells and/or Deiters’ cells), loose

Front 20

Which type of hair cells are embedded in the tectorial membrane?

Back 20

Outer Hair Cells

Front 21

Cochlea innervated by ____________________________

Back 21

cn VIII (aud. Nerve or stato-acoustic nerve)

Front 22

What are the 2 divisions of the auditory nerve?

Back 22

vestibular
auditory

Front 23

Approximately how many neurons exist in humans?

Back 23

30,000

Front 24

On its way to brain cn VIII passes through the ________________________________

Back 24

Internal auditory canal

Front 25

The internal auditory canal extends from the _____________ to ______________________

Back 25

base of the cochlea, petrous portion of temporal bone

Front 26

Cell bodies of CN VIII constitute the ______________, found in the modiolus

Back 26

spiral ganglia

Front 27

The majority of these neurons are ____________ neurons that carry sensory info from the hair cell to the brain.

Back 27

Afferent

Front 28

Some of the fibers are __________ neurons that carry information from brain to cochlea.

Back 28

Efferent

Front 29

What are Type 1 auditory neurons of the spiral ganglia?

Back 29

large myelinated bipolar neurons

Front 30

What are Type II auditory neurons of the spiral ganglia?

Back 30

small unmyelinated pseudo-monopolar neurons

Front 31

As fibers enter cochlea approximately 90-95% of fibers, which are called ______________ go to IHCs. Which type of neurons are these?

Back 31

Inner radial fibers, Type I bipolar neurons

Front 32

The remaining 5-10% fibers that don't go to IHCs are called ________________ and go to the OHCs. Which type of neurons are these?

Back 32

Outer spiral fibers, Type II psuedo-monopolar neurons

Front 33

The remaining 5-10% fibers that don't go to IHCs are called outer spiral fibers and go to the OHCs. Which type of neurons are these?

Back 33

Type II pseudo-monopolar neurons

Front 34

Nerve fibers may be myelinated or unmyelinated before exiting the ___________________

Back 34

habenula perforata(e)

Front 35

once nerve fibers enter into cochlea they are all _________________-

Back 35

unmyelinated

Front 36

When compared to neurons, axons to the OHCs take a more __________ course

Back 36

oblique

Front 37

Describe the shape of the auditory nerve.

Back 37

Auditory nerve is a twisted trunk

Front 38

The core of the auditory nerve is made up of _____________________

Back 38

fibers from the cochlear apex

Front 39

The Auditory Nerve exits cochlea and courses thru __________________

Back 39

internal auditory canal

Front 40

The auditory nerve enters brain at ______________

Back 40

lower pons

Front 41

Spiral ganglion cells represent _____________ neurons

Back 41

first order

Front 42

The pathways of the auditory nerves are complex. Some fibers course in an ____________ fashion and others _____________

Back 42

ipsilateral, contralaterally

Front 43

Fibers are labeled according to _______________________________

Back 43

# of synapses (connnections)

Front 44

__________________ auditory nerve fibers project to the lateral regions of the cochlear nucleus

Back 44

Low frequency

Front 45

CN VIII fibers are called ___________

Back 45

first order

Front 46

As first order fibers enter the brainstem they synapse with cell bodies in the ________________________

Back 46

dorsal and ventral cochlear nucleus

Front 47

2nd order neurons arise from ______________________

Back 47

cochlear nuclei

Front 48

Low frequency auditory nerve fibers project to the____________________ of the cochlear nucleus

Back 48

lateral regions

Front 49

_____________________ auditory fibers project to the the medial regions of the dorsal cochlear nucleus (DCN) and posterior ventral cochlear nucleus (PVCN) and to the medial and dorsal anterior ventral cochlear nucleus (AVCN)

Back 49

High frequency